1. Field of Invention.
The invention relates to tools and techniques employed for removing spin-on oil filters from the engine blocks of internal combustion engines.
The removal of a spin-on type oil filter cartridge from the engine block of an internal combustion engine as required for routine servicing and change of lubricating oil, is frequently fraught with considerable difficulty, bruised hands, skinned knuckles and painful burning of the mechanic's hands and arms when the latter are inadvertently brought into contact with hot engine parts. Special wrenches have been designed to facilitate removal of the filters but the maze of parts typically crowded into the engine compartment interferes with the use of such wrenches and, in many instances, makes such use totally impractical. Accordingly, such spin-on filter cartridges are commonly removed by pounding a large chisel, screwdriver or the like through the oil filter canister, spreading rags around the area to contain the oil which will spill, and with the chisel or screwdriver in place striking it with a hammer or mallet to unthread the filter.
2. Description of Prior Art.
Typical of prior art tools and techniques for removing spin-on oil filter cartridges are U.S. Pat. Nos. 3,728,916 and 3,962,936. The tool disclosed in both of these patents comprises the combination of a strap bight adapted to fit around a filter cartridge and a wrench with the structure so arranged with rotation of the wrench tightens the bight around the cartridge and at the same time turns it in either wrenching direction. The wrench consists of a torquing lever which of necessity must move in close proximity to the cartridge and, accordingly, in close proximity to the engine block, head, manifolds and other parts. Typically, the area around the filter cartridge is crowded and relatively inaccessible making it awkward, if not impossible, to swing a torquing lever through any substantial distance.